Input stage for a motor controller, and motor controller, especially for an electric motor

The invention relates to an input stage (1) for a motor controller (2), especially a motor controller for an electric motor, the input stage (1) being provided with an input (3) for inputting an input signal and an output (4) for connection to the motor controller (2). The input stage (1) is designed to generate a control signal from an input signal between a first voltage Uunten and a second voltage Uoben>Uunten and output said control signal as a parameter to the motor controller (2) via the output (4). In order to be able to simultaneously use the control input (13) for communicating, the input stage (1) comprises a first comparator (5) for comparing the input signal with a first threshold voltage Us1>Uoben as well as a data output unit (10). The data output unit (10) generates a communication signal on the basis of at least one portion of the input signal. When the input signal reaches or exceeds the first threshold voltage Us1, the first comparator (5) outputs an activation signal which activates output of the communication signal to the output (4) by the data output unit (10). The invention further relates to a motor controller, especially for an electric motor, comprising a corresponding input stage, and to an interface adapter for the input stage.